Conventionally, there has been known an application which uses an image capturing apparatus to capture an image where a subject is present in a background and a background image where the subject is absent, to generate difference information from the background image and the image where the subject is present, and to extract the subject from the captured image. An example of such application is disclosed in JP-A-10-021408.
However, when an image where a subject is present in a background and a background image where the subject is absent are captured in two separate shots as shown in the publication, JP-A-10-021408, the angle of view is likely to move between the two shots. Therefore, a background part may be misidentified as the subject due to a difference in each pixel value of the background itself in a process for extracting the subject, so that the subject may not be extracted properly. In this case, images have to be captured again, and the operation for generating a cut-out image of the subject becomes troublesome.